Hydrogen peroxide detection nanosensor array for biosensor development

A recessed disk nanoelectrode array sensor, improving hydrogen peroxide determination is reported here. The nanoarray of electrodes is fabricated on a gold surface by using nanosphere lithography. The active surface of the obtained array was subsequently modified, by electrodeposition, with Prussian Blue (PB) and polypyrrole (PPy), in order to obtain sensitive, low cost and reliable probes. This modification helped in increasing the electrochemical active area (PPy) and thanks to the use of PB, the potential applied in the amperometric measurements can be shifted to 0.0 V, characteristic very useful for the future applications. Moreover, this configuration provides sufficient operational stability of sensing. The immobilization of different layers on the electrode surface, the electrochemical characterization and analytical performances of the nanoelectrode array have been studied and discussed. Detection limit of 10−9 M and a linear calibration range up to 10−4 M were obtained. The Relative Standard Deviation was 3.5% and 6% for intra-electrode and inter-electrode assay, respectively.